1. Field of the Invention
The present invention relates to a static/dynamic multi-function measuring device for a linear unit, and more particularly, to a high-speed, high-precision measuring device for simultaneously measuring a parallel alignment of a moving slide block of the linear unit, a linear error of a slide rail, and testing errors of the slide block moving in the vibrating and the rolling direction.
2. Description of the Prior Art
As semiconductor industry and nanotechnology evolve, there are growing demands for high precision automatic foundations. One of the most popular driving components for foundations is the linear unit. In recent years, the applications of linear units are becoming more versatile and heading into the nanometer range, however, the detection techniques for linear units is just emerging, how to enhance the abilities of the linear units is now an imperative mission.
Presently, most precision detection techniques for linear units are based on traditional detection method using linear variable differential transformers (LVDT) and measuring meters, in one embodiment, the precision detection technique uses granite surface having high level precision as reference plane and attaches a measuring meter to a slide block base, thereafter it moves the slide block and measures the precision by the measuring meter.
However, due to the long requiring length for a common linear unit, it takes several steps to finish detecting the precision of the whole linear unit by using the above measuring method. Besides, each detecting step would generate an error, for example, it takes a while to measure a four meter long guide rail, and it also produces a result with high uncertainty, therefore it is not suitable for detecting a linear unit with the highest precision level “up” (parallel alignment: 2 μm/300 mm); furthermore, as to high precision requirements, the traditional detection method cannot provide better detection quality and more detection statistics to ensure the quality of the linear unit.
Therefore, the inventor of the present invention tries to improve the traditional detection techniques for linear unit by proposing a plurality of non-contact measuring methods using driving mechanisms with low friction to detect errors generated from the linear unit when it's moving, thereby implementing high speed and high precision requirements.